138967-33-6Relevant academic research and scientific papers
Alkaloid constituents from flower buds and leaves of sacred lotus (Nelumbo nucifera, Nymphaeaceae) with melanogenesis inhibitory activity in B16 melanoma cells
Nakamura, Seikou,Nakashima, Souichi,Tanabe, Genzo,Oda, Yoshimi,Yokota, Nami,Fujimoto, Katsuyoshi,Matsumoto, Takahiro,Sakuma, Rika,Ohta, Tomoe,Ogawa, Keiko,Nishida, Shino,Miki, Hisako,Matsuda, Hisashi,Muraoka, Osamu,Yoshikawa, Masayuki
, p. 779 - 787 (2013/02/25)
Methanolic extracts from the flower buds and leaves of sacred lotus (Nelumbo nucifera, Nymphaeaceae) were found to show inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the methanolic extracts, a new alkaloid, N-methylasimilobine N-oxide, was isolated together with eleven benzylisoquinoline alkaloids. The absolute stereostructure of the new alkaloid was determined from chemical and physicochemical evidence. Among the constituents isolated, nuciferine, N-methylasimilobine, (-)-lirinidine, and 2-hydroxy-1-methoxy-6a,7-dehydroaporphine showed potent inhibition of melanogenesis. Comparison of the inhibitory activities of synthetic related alkaloids facilitated characterization of the structure-activity relationships of aporphine- and benzylisoquinoline-type alkaloids. In addition, 3-30 μM nuciferine and N-methylasimilobine inhibited the expression of tyrosinase mRNA, 3-30 μM N-methylasimilobine inhibited the expression of TRP-1 mRNA, and 10-30 μM nuciferine inhibited the expression of TRP-2 mRNA.
Synthesis of benzyl substituted tetrahydropyridines and 1,2,3,4- tetrahydroisoquinolines via acid catalyzed cyclization of γ,δ-unsaturated N-formyl-N-styryl amines
Meuzelaar, Gerrit J.,Maatz.ast, Leendert,Sheldon, Roger A.
, p. 4481 - 4488 (2007/10/03)
Acid-catalyzed cyclization of N-(3-methylbut-3-enyl)-N-styrylformamides 1-3 in the presence of 9-BBN triflate gave access to 2-benzyl-1-formyl-4- methyl-1,2,5,6-tetrahydropyridines 4a-6a and minor amounts of the isomeric 1,2,3,6-tetrahydropyridines 4b-6b.
A highly efficient synthesis of 1-methyl-, 1-benzyl-, and 1-phenyl-1,2,3,4-tetrahydroisoquinolines by a modified pummerer reaction
Shinohara, Tatsumi,Takeda, Akira,Toda, Jun,Terasawa, Noriyo,Sano, Takehiro
, p. 555 - 565 (2007/10/03)
(±)-1-Methyl- (13b), (±)-1-benzyl- (13c), and (±)-1-phenyl- (13d)-1,2,3,4-tetrahydroisoquinolines, which are supposed to participate in the pathogenesis of Parkinson's disease, were prepared by using a modified Pummerer reaction as a key step in excellent overall yields from the commercially available ketones (4b-c).
